Light emitting diodes (LEDs) constitute a light emitting source by using GaAs, AlGaAs, GaN, InGaN, and InGaAlP-based compound semiconductor materials, thereby realizing various colors. Such LEDs have been applied to various fields such as a lightening indicator, a character indicator, and an image indicator using colors.
In general, characteristics of the LEDs are determined depending on materials, colors, brightness, and the range of brightness intensity of a compound semiconductor, and mainly affected by a package structure of mounting an LED chip.
FIG. 1 is a sectional view showing a related art light emitting device.
Referring to FIG. 1, a reflecting cup 20 is fabricated through an injection molding process using white plastics, and lead frames 11, which are electrically insulated from each other, are formed in a cavity of the reflecting cup 20. The lead frame 11 is provided with an LED chip electrically bonded thereto by a wire. Both end portions of the lead frames 11 pass through the reflecting cup 20 such that the end portions are used as electrode terminals.
The cavity of the reflecting cup 20 is filled with a mold part 40 including transparent epoxy resin. The mold part 40 includes a yellow fluorescent substance such as YAG:Ce fluorescent substance. The yellow fluorescent substance absorbs blue light emitted from a blue LED chip 30 and is excited by means of the blue light, so that yellow light can be emitted. The yellow light is mixed with the blue light so that white light is emitted. Accordingly, a white LED can be realized.
In this case, the reflecting cup 20 has a length in the range of about 2 mm to 4 mm, a width in the range of about 0.4 mm to 2 mm, and a height in the range of about 0.6 mm to 2 mm.
In such a light emitting device, the lead frame 11 is arranged in the cavity of the reflecting cup 20, and the LED chip 30 is mounted on the lead frame 11. However, the blue LED chip 30 cannot easily be mounted due to the space limitation of the cavity of the reflecting cup 20. Accordingly, the productivity of the light emitting device may decrease, and the defect rate of the light emitting device may increase.
In addition, since the mold part 40 having the fluorescent substance cannot be easily inserted into the reflecting cup 20 due to the narrow cavity of the reflecting cup 20, the color reproduction and the light efficiency of white light emitted from a side light emission type LED may be degraded.